/* 五彩导航栏 */
.nav a {
  display: inline-block;
  width: 120px;
  height: 40px;
  text-align: center;
  line-height: 32px;
  text-decoration: none;
  font-size: 12px;
  color: #000;
}

.bg1 {
  background: url(../img/bg1.png) no-repeat center;
}
.bg2 {
  background: url(../img/bg2.png) no-repeat center;
}
.bg3 {
  background: url(../img/bg3.png) no-repeat center;
}
.bg4 {
  background: url(../img/bg4.png) no-repeat center;
}

.bg1:hover, .bg2:hover, .bg3:hover, .bg4:hover {
  background: url(../img/bg5.png) no-repeat center;
}